Bahtinov Mask Focus and Cap Cover for ZWO Seestar S50,Lens Cap for Seestar S50 Accessories for ZWO Seestar S50 2pcs,Made of Plastics,Black

I think whoever was making these took the first couple reviews to heart, because there is clearly an added, thin layer of tape around both the cap and Bahtinov mask. The problem is, that makes the caps TOO tight now.But what I did to fix that was take a flathead screwdriver (an X-acto type hobby knife or utility knife would work too), and scraped off about half of the tape. Then the caps fit snugly, without being TOO tight - which they were with all the tape on them.Bahtinov mask looks good. The regular cap is nice and thin - BUT - be very careful if you close the Seestar with it on. It will wind up bumping the bottom of the case when it tries to finish closing. So probably better to use this when you have the Seestar outside and just want to cover the lens for a period of time. I wouldn't use it to cover the lens when stored.Other than that - and fixing the tape - these seem fine and I'll undoubtedly use them quite a bit.

Mask works great for focusing my SeeStar but the cover is loose and kept falling off when it tilted down during shutdown.

Both these parts come with a felt-type o-ring, apparently to make a snug fit. Unfortunately, the felt liner makes the fit so tight it is very difficult to attach/remove. It took me several minutes to rub off the liners, which make the fit much better. Still snug, but not overly so. Would recommend looking at other options.

These covers simply fall out of the lense on the S50. They do not press fit like the solar filter. Makes the dust cover basically useless. You spent allot on the Seestar, find something that actually works to protect it.

The items did not fit the opening of the telescope, they were much too small and fell right out. Don’t waste your money.

The original reviews complain that these are too small and fall out of the Seestar S50. Then a new review states that they have added tape to make it thicker, and now it is too tight. Also, you can’t close the Seestar with the lens cap on.So, I received mine, and they have now cut about 20% of the tape off, but they left the sticky adhesive from the tape on it. I wouldn’t consider installing this on my Seestar, so I got some GooGone and removed the adhesive with a q-tip.It’s still quite tight, but the Bahtinov Mask works. I always close the Seestar when my session is done, so I don’t have much use for a cap that can only be applied when it is open.I’m sorry, but think these guys should go back to the drawing board and create Seestar accessories that fit correctly without needing modifications.